Bioclimatic approach to assessing the potential impact of climate change on two flea beetle (Coleoptera: Chrysomelidae) species in Canada

Both the striped flea beetle, Phyllotreta striolata (Fabricius), and crucifer flea beetle, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae), are invasive alien species to North America. In western Canada, they are the most significant insect pests of cruciferous (Brassicaceae) crops. Climate is the one of the most dominant factors regulating the geographic distribution and population density of most insect species. Recent bioclimatic simulation models of the two flea beetle species fostered a better understanding of how the two species responded to selected climate variables. They demonstrated that selected climate variables increased population densities and geographic range of the two species. General circulation model inputs were applied in this study to assess the impact of a changing climate on the response of P. cruciferae and P. striolata populations. Model output, using the climate change scenarios, predicted that both P. cruciferae and P. striolata populations will shift north in future climates and the degree of geographic overlap between these two species will be greater than for current climate. This suggests that the two species could potentially cause economic losses over an expanded area in the future.